Guide to the INDRA

^{The INDRA is a port of the Baystation 12 R-UST with significant modifications for the Aurora server.}

The INDRA is an experimental fusion reactor that acts as an alternative power source on the Horizon. It consists of a fusion core, fuel injectors, a gyrotron and a few control consoles. Fuel comes in two forms: gas injection into the chamber via an injector pump (the most efficient), and as a fuel rod loaded into Injectors (far less efficient, but necessary for some reactant types). If mismanaged, the INDRA can cause extreme amounts of destruction to the adjacent decks and surrounding area.

As for what INDRA stands for, that's a subject of much debate. Some say it stands for INDependent Reactor, Aneutronic. Others say it stands for INDRA. Who knows, really?

Priming, starting, and maintaining the Horizon is the job of the engineering department. However, some scientists may be brought in for certain collaborative efforts with the permission of the engineering department.

Basic Principles

The INDRA is about as complex as the Supermatter Engine. The basic operating principles are as follows:

The Fusion Core

The fusion core is the centerpiece of the INDRA, all reactions take place there and it is where the power is generated.

First a note on safety - the reactor produces large quantities of radiation when operational, depending on the active reactions. Check with a geiger counter to see. Ensure that you wear appropriate protective equipment when entering the reactor chamber during or after the reactor has been running.

The INDRA is capable of creating a devastating EMP if operated improperly. Do not exceed the limits specified in this guide, or it will rapidly self-annihilate. The INDRA will create this EMP if plasma temperatures are above 720000K when its instability reaches 100% or if it is turned off without being allowed to cool first. Instability, disaster, and disaster avoidance will be discussed below.

INDRA Control Interface

INDRA control console interface.

The fusion core is controlled by the INDRA core control console in the monitoring room. As you can see from the image, this tracks many properties of the fusion core.

• Power Status - This tells you the current power output and power draw of the Fusion Core. Power draw is dependent on the field strength, and power output is dependent on the fusion reactions taking place within the core.
• Field Strength - This determines the field size of the fusion core; this is important for catching fuel pellets and can be set between 20 and 120 for the default INDRA configuration; 20 is the safest value. If any object besides the core (or atmospheric machinery) is inside the INDRA chamber while it is online, it will interfere with the magnetic field, causing a catastrophic rise in instability and near-instantaneous destruction of the INDRA. Increasing the field strength has several effects:

  * Field Strength scales the size of the torus. With higher field strength, the diameter of the magnetic torus will increase (20-40: 1m, 40-80: 3m, 80-120: 5m)
  * Field Strength scales power output per temperature. With higher field strength, each degree Kelvin will produce drastically more electricity. This is what a skilled Engineer will adjust Field Strength to optimize for.
  * Field Strength scales plasma temperature entropy. With higher field strength, each tick will lose more temp and produce more radiation.
  * Field Strength scales instability increase. With higher field strength, more instability for a given reaction will be produced each tick. This, as well as temperature entropy, is what a skilled Engineer must monitor and manage while optimizing energy output.

• Instability - Instability is raised by two things: the fusion reactions taking place and the fusion core field touching machinery or objects. It is controlled by using the Gyrotron to fire a beam of energy into the fusion core field that maintains its containment. If your instability is steadily rising despite the gyrotron then you must immediately adjust the Gyrotron settings and/or reduce the amount of reactants being added to the field.
• Plasma temperature - This determines the reactions that can take place. Initially your fusion core will be at room temperature, and it will take some time to warm up. Once it is above a few thousand kelvin the rest of the reactions will kick in and it will keep itself stable. When turning off the fusion core this value must be below 720000K or it will cause an EMP and destruction of the INDRA containment, likely flooding engineering and research with extremely hot gas. To cool this down stop adding reactants and turn the gyrotron power up, then wait.
• Reactants - This is a list of all current reactants in the field. Every tick of the INDRA, it will try and react these reactants together and create some radiation, instability and power based on what reactions are possible. Reactants exceeding 10,000 total reactants will be removed and turned into radiation (this is not something to worry about, just don't try to add more reactants if you are consistently hitting this threshold).

The Fuel Injectors

These are used to add solid fuel into the INDRA. They are controlled using the Fuel Injection Control Computer within the control room. They must be provided with a fuel rod that can be created by putting solid fuel types into the Fuel Compressor, and then toggled on from their control computer. They will then start firing pellets through the glass into the fusion core field and be absorbed. There are a few different types of fuel materials, but the most common are tritium and deuterium. Iron may be used for other purposes, and there are various other rarer materials not worth covering here. Injecting deuterium and tritium using fuel rods is far less efficient than gas injection, but can be useful for tweaking reactor behavior.

The Kinetic Harvester

This is used to extract certain materials from the plasma field and rapidly compile them into usable ingots. It is another massive power consumer, but extremely valuable. While the volumes of material it can produce is marginal compared to what Miners can bring in, it is nonetheless a valuable supplement to the ship's resource income. When the Kinetic Harvester is turned on, it will display a list of materials currently in the core that can be siphoned off (i.e. you must already be producing the material for it to appear in the list). By enabling a given material, the Harvester will pull reactants from the core for ingot production. This is critical in the case of gold, as gold is a powerful reactor poison and failing to siphon it off can result in drastic temperature decreases. This may seem confusing at first, but the behavior is explained below in the Additional Reactions section.

Setup

Now that you understand the important components of the INDRA, we will discuss how to set it up at the start of the shift. It is initially in a completely inert state.

If you already have power supplied by the Supermatter Reactor:

• Ensure that the INDRA reactor is receiving external power; both the fusion core and gyrotron are heavy power consumers.
• From the INDRA gas storage locker, connect the 'Fusion Reactor Cold Ignition Mix' canister to one of the connector ports. This is a 50-50 mixture of Deuterium and Tritium, which is the only mixture that can start fusing at low temperatures.
• Set the core to Field Strength 20, then turn on the fusion core.
• Set the gyrotron to Fire Delay 2, Power 25, then turn on the gyrotron. There may be an initial burst in instability when turning the reactor on - if you have allowed fuel to build up. This is fine, it should level out quickly.
• Enable the gas pump connecting the Fusion Reactor Cold Ignition Mix canister to the reactor core. By default, this pump is set to 10 kPa; this is fine, because very little gas is actually needed to feed the generator.
• Return to the monitoring room and watch the temperature and power rise on the fusion core console.
• Make sure that the instability is being managed by the gyrotron (less than 40%). A spike or two above 50% is possible, but again, it should level out quickly.
• Increase the gyrotron's power setting to 40. You can adjust this up or down based on your observation of reactor temperature and instability, along with fire delay, but you should always ensure that instability remains below 40%. If a spike past this occurs, increase gyrotron power and/or reduce fire delay.

If the shift has just started, or you otherwise have no available external power on the ship:

• The fusion core and gyrotron have a heavy power drain when operational. At round start, you will need to use the Advanced Portable Generator to jumpstart the reactor.
• To do this, also disable the Grid Output breaker as well as the Grid Output PSU's input while using the generator. This guarantees that the portable generator's power output only supplies the fusion core and gyrotron. Do not modify the settings of the breaker or PSU of the Containment Grid, located in the tiny room on the right side of the reactor chamber.
• Fuel the generator, set power output to any value between 1 and 4, and turn it on. The maximum output level, 5, causes it to overheat much faster and we don't need that much power.
• In the INDRA gas storage locker, connect the 'Fusion Reactor Cold Ignition Mix' canister to one of the connector ports.
• Set the core to Field Strength 20, then turn on the fusion core.
• Set the gyrotron to Fire Delay 2, Power 5, then turn on the gyrotron.
• Enable the gas pump connecting the Fusion Reactor Cold Ignition Mix canister to the reactor core.
• Return to the monitoring room and watch the temperature and power rise on the fusion core console.
• Because the Advanced Portable Generator has a relatively low power output, the gyrotron must start at a low power state. As power output rises, you MUST also increase the gyrotron's Power setting as the fusion core starts producing more and more power. Stay in the monitoring room and keep nudging gyrotron power up as you see available power increasing.
• Once you have increased the gyrotron's power setting to 40 and it is firing regularly, go back into the reactor chamber and turn off the Advanced Portable Generator. If it runs for too long, it can overheat and explode. This is often bad for the reactor.
• With power output from the fusion reactor stable, you can again re-enable the Output Grid breaker bypass and/or PSU input.

You have now set up the INDRA for a deuterium-tritium reaction, which is the simplest power-positive reaction.

The power from the INDRA will not be fully utilized until you adjust the SMES. Make what upgrades you desire, but if nothing else at least make sure input and output are maximized.

What Does Disaster Look Like

Failure of the fusion core's magnetic containment field results in all the plasma contained in the core to be released into the atmosphere. This can occur either due to instability reaching 100% or by an emergency override shutdown on the main console.

At temperatures below 720000K, nothing else will occur; the gas can be vented out the back (using the core vent blast door controls mentioned below), or else it will quickly destroy the core containment chamber and fill the reactor with superheated gas.

At temperatures above 720000K, the magnetic containment field failure will also result in a powerful electromagnetic pulse (EMP) effect, scaling with the current plasma temperature. At extremely high temperatures, this can potentially EMP the entire ship.

This should be avoided, as EMPing the entire ship can result in mass casualties and/or getting yelled at by the Captain, Chief Engineer, and anyone else who knows you did it.

Emergency Shutdown Procedures

In the event that you need to shutdown the INDRA quickly follow these steps:

• Set the gyrotron to maximum (sustainable) power and minimum firing delay.
• Turn off all fuel injectors.
• Turn off both gas pumps.
• Monitor the fusion core temperature and instability; your goal now is to reduce gyrotron power to the lowest safe state (instability remaining below 40%).
• With no additional fuel being added, the INDRA will begin to cool; however, fusion chains will continue to occur for some time.
• The shutdown command from the fusion core will require override when temperatures are above 1000K, but the reactor can be shut down semi-safely while below 720000K.
• Shutting down the reactor will cause the gases currently in the magnetic field to be dumped into the core's atmosphere at their current temperature. Ensure the core vent blast doors are opened before doing this; the controls are located at the back of the INDRA reactor room.
• It is far preferable to allow the core to reach temperatures below 5000K before shutting it down, as this will prevent any damage to the superstructure.

Additional Reactions

The INDRA is not limited to hydrogen isotopes. There are a variety of fusion reactions that can be performed, with varying levels of danger and usefulness. While all reactor configurations rely on the initial 1:1 deuterium-tritium burn, many more primary power reactions are possible.

Your first and best resource for additional reactions is the in-game Fusion Codex app, available on Engineering PDAs and computer consoles.

Hydrogen Burning

Hydrogen only begins to fuse at 400000K, but is a powerful addition to a standard deut-trit mixture. Connecting a hydrogen can to the second available gas connector and enabling it after passing the 400000K plasma temperature mark will result in a marked jump in power.

Helium-3 Burning

Helium-3 is a very expensive fusion fuel, highly sought after because not only does it produce massive amounts of power when fusing, but it also does so extremely cleanly. Deuterium-tritium fusion produces massive amounts of radiation, but Helium-3 produces almost none in comparison, and is also far more stable. It requires a temperature of at least 3.2 million K to start fusing. Trace amounts of Helium-3 are generated by other fusion chains, but this is highly inefficient to rely upon compared to a direct feed. The Horizon comes with a single Helium-3 can available at shift start.

Iron Shot

Iron is a very useful reaction for the ship as a whole, but not so much the engineering department specifically. When inserting at least one hundred units of liquid iron (the kind you'd get from chemistry) or 5 iron ingots into the fuel compressor, you get an iron fuel rod, which can be inserted into the fuel injectors. Iron fuses with itself and creates instability spikes while generating lead, gold, silver, and platinum. Research and operations will be especially pleased to receive these, but there are two catches: one, iron only fuses above 2.8 million degrees. Two, every time it does, it will drastically cool the INDRA core (iron poisoning). Iron reactions are best paired with a Helium-3 burning to prevent it cooling down the core to uselessness. What's more, gold is an even stronger reactor poison than iron; failing to enable and configure the Kinetic Harvester to remove gold from the core can cause the reactor to quickly stall out. A clever engineer could also use this behavior to cool down a reactor that has gotten too hot.

Phoron Shot

The more dangerous little brother to the Iron reaction. With 5 phoron crystals, a phoron rod can be created that fuses with iron plasma above 4 million degrees. It generates osmium, borosilicate glass, and uranium. The first two are of dubious usefulness on the average shift, but research values uranium shipments highly. In exchange, phoron reactions spike instability quite high and saps core temperature much like iron reactions do. They can still be managed with a strong gyrotron even when being run with Helium-3 but have a little caution.

Other Reactions

There are other reactants available, but they are either of dubious usefulness, incredibly difficult to acquire, actively harmful, or all three. Oxygen, for instance, spikes radiation to lethal levels while generating no power. Metallic hydrogen fusion is the only fusion chain that has a negative instability coefficient, making it hugely useful for stabilizing otherwise unmanageable mixtures. For the mad or the outright evil, certain forms of supermatter crystal may fit into the fuel compressor, and a single Supermatter Fuel Rod is stored in the Secure Technical Storage vault. A Chief Engineer sufficient deranged could authorize its use with a good plan in place; or a nefarious engineer might take it upon themselves to experiment. Just remember to ahelp to confirm before potentially blowing up reactors as an antagonist!

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Engineering Department
Head of Department	Chief Engineer
Personnel	Engineer - Atmospheric Technician
Useful Guides	Guide to Atmospherics - Supermatter Engine - Guide to the INDRA - Turbine Engine - Guide to Thrusters - Telecommunications - Integrated Electronics